Field of the Invention
Embodiments presented herein provide techniques for creating virtual terrain maps, including example-based editing of virtual terrain maps.
Description of the Related Art
Virtual terrains are used in numerous applications including animation, films, video games, landscape visualization and flight simulators. Modeling such virtual terrains to resemble natural landscapes can be challenging due to the characteristics of natural landscapes. At a macro level, natural landscapes tend to present distinctive geological features such as height, shape, and distribution of roughness. However, at a micro level, natural landscapes are inherently stochastic. These characteristics of natural landscapes make it difficult for artists to manually model virtual terrains by, e.g., extruding elevation meshes.
A variety of procedural approaches have been developed to automatically generate virtual terrains. Such procedural approaches typically take as input user-specified parameter values (e.g., values for noise parameters indicating roughness of the terrain) and generate virtual terrains according to the input parameter values. However, the parameterizations that are used are often unintuitive for artists, with little visual correlation between the input parameter values and the output terrain. Further, artists lack control over the final, automatically generated terrain aside from modifying values of the available parameters. As a result, artists have resorted to an example-based manual approach in which they collect reference and inspiration data from the real world (e.g., sketches, elevation maps, and satellite images) and sculpt virtual terrains using three-dimensional (3D) software packages, in a lengthy and cumbersome process.